The invention relates to a method of inner lining bearing lugs of metal, preferably iron bearing parts, and to an apparatus which constitutes or comprises a welding head and can be used for the practice of the method.
The term bearing lugs is intended to denote not only the bearing lugs of bolt bearings but also other parts having circular cylindrical holes and being subject to wear and tear by engaging parts during operation.
Depending upon the normally high mechanical, often even one-sided strain, the bolt bearings of heavy metal devices are subjected to pronounced wear and tear. Normally, the wear upon the bolt can easily be repaired by inserting a new bolt. The wear upon the bearing lugs leads to worn-out lugs. For the repair it is known to enlarge the opening of a worn-out lug, and then to weld into the enlarged opening a prefabricated bearing sleeve or socket to thus provide a restored bearing lug. Such repair of the lug requires a great deal of energy and also leads to unwanted warping of the bearing bows of the respective lugs as a result of the necessary welding. The bearing sleeve has to consist of relatively soft iron because, if it is high-grade tempered, it snaps off the welding. This, however, entails a more pronounced wear and tear upon the newly installed bearing lug.